Biomagnification and Algal blooms homework

Which organism in the food web would

contain the highest concentration of chemical pollutants?

• producers

• primary consumers

• secondary consumers

• tertiary consumers

Which organism in the food web shown to the right would

contain the lowest concentration of chemical pollutants?

• producers

• primary consumers

• secondary consumers

• tertiary consumers

Which type of tissue that is found in greater amounts in

top predators accounts most for the accumulation of chemical

toxins?

• nervous tissue

• fat tissue

• muscle tissue

The accumulation of heavy metals or other pollutants causes

a decline in the population of predatory birds because –

• heavy metals make it difficult for the birds to hunt

• pesticides diminish the amount of available food

• the pollutants interfere with bird reproduction

Chemical pesticides tend to be used in terrestrial ecosystems, but they are commonly found in the tissues of aquatic organisms. Because of this, birds and other animals with a diet high in fish commonly suffer the effects of biological magnification. How do these pesticides end up in these aquatic ecosystems?

• Pesticides evaporate and are delivered to water sources by rainfall

• Land animals containing pollutants die and decompose in waterways

• Pesticides are carried to water sources by freshwater runoff.

Algae grow rapidly when certain nutrients are added to the water supply causing an algal bloom. Eutrophication describes the process of adding nutrients to the water supply. What human activity is most responsible for the eutrophication that leads to algal blooms?

• Burning fossil fuels

• Disposing of pesticides

• Fertilizer for food crops

The rapid growth of algae, called an algal bloom, can lead to the formation of dead zones that cannot sustain aquatic life. This is mainly because the algal bloom lowers the amount of –

• chemical pollutants

• dissolved oxygen

• freshwater runoff

Which organism shown in the food chain above would contain the greatest concentration of chemical pollutants?

• phytoplankton

• krill

• tuna

• shark

Most health experts recommend only eating tuna a few times a week and only eating shark a few times a month. Why would health experts have this view of eating these fish?

Hint: think biomagnification

• Most fish are low in protein and high in saturated fats which can cause health problems

• People with diets high in fish tend to have high blood pressure and heart issues

• Eating these fish could result in the buildup of pollutants in the fat tissue of humans

Pollution resulting from the use of fertilizers and the disposal of sewage from humans and livestock can lead to an algal bloom. The effects of these pollutants on algae growth can be intensified as a result of which of the following?

• The decreased use of solar power

• An increase in freshwater runoff

• An increase in organic farming practices